N.L. CuelloA.M. CleefG. Aymardhttp://dare.uva.nl/record/370791nulljournalArticle02111322Ramal de Guaramacal is an outlier and lower elevation mountain range located at the northeastern end of the Venezuelan Andes. Phytogeographical patterns and affinities of the low altitude and wet vascular páramo flora of Ramal de Guaramacal, have been studied with emphasis in to the analysis of the floristic connections of the Guaramacal páramo flora with the neighboring dry páramos of the Sierra Nevada de Mérida and other páramo floras of the northern Andes and Central America. A total of 252 vascular plant taxa belonging to 150 genera and 69 families were recorded from the study area. The most species rich families are Asteraceae, Poaceae, Ericaceae and Orchidaceae, followed by the ferns families Grammitidaceae and Lycopodiacae. The most diverse genera are the ferns Elaphoglossum, Huperzia and Hymenophyllum. The analysis of generic phytogeographical composition of páramo flora showed that 52.8% of the genera are Tropical. The Temperate component is represented by 33.3% of the genera and the Cosmopolitan component is represented by 13.9% of the genera. The Neotropical montane element (38.9%) is high in Guaramacal páramo, the Páramo endemic element (1.9%) and the Andean alpine element (0.9%) and represented by only one genus (Lachemilla) are low compared to other páramo areas. The vascular flora of Páramo de Guaramacal is largely composed of (1) a group of Neotropical widespread distributed species (32%), (2) a group of Andean distributed species (49%), part of them confined to the Northern Andes and part widespread in the Andes from Colombia to Bolivia, and (3) a group of Venezuelan endemics (19%). From an eight páramo flora comparative dataset, the closest relationships among páramos is observed between the generic páramo floras of the Colombian Cordillera Oriental of Sumapáz and Sierra Nevada del Cocuy, which are both closely related to that of the Sierra Nevada de Mérida in Venezuela. The generic páramo flora of Ramal de Guaramacal shows the closest relationship to southern Ecuador páramo flora of Podo - carpus Biosphere Reserve. According to Detrended Correspondance Analysis and Principal Component Analysis ordination results, most of the variations in páramo floras may represent a response to differences in ambient humidity.2010 02111322 urn:nbn:nl:ui:29-370791 67 2 177 193